I was able to replicate this issue in a very simple way, within a new project created with the standard Xcode template, to which I added a Swift Package as a library (MyLibrary).
This is the Package definition:
// swift-tools-version: 6.3
// The swift-tools-version declares the minimum version of Swift required to build this package.
import PackageDescription
let package = Package(
name: "MyLibrary",
platforms: [.iOS(.v18)],
products: [
// Products define the executables and libraries a package produces, making them visible to other packages.
.library(
name: "MyLibrary",
targets: ["MyLibrary"]
),
],
targets: [
// Targets are the basic building blocks of a package, defining a module or a test suite.
// Targets can depend on other targets in this package and products from dependencies.
.target(
name: "MyLibrary",
path: "Sources/MyLibrary"
),
],
swiftLanguageModes: [.v6]
)
If the target name is equal to library name (MyLibrary) the preview of SwiftUIView works as expected.
If I change the target name (for example MyLibrary1), the preview does not work any longer.
The Diagnostics dialog reports that:
== PREVIEW UPDATE ERROR:
GroupRecordingError
Error encountered during update group #64
==================================
| NoBuiltTargetDescriptionFoundForTranslationUnit: Could not find target description for “SwiftUIView.swift”
|
| The list of source files that produce object files did not contain this file to be previewed.
|
| Check to make sure it is not excluded using the `EXCLUDED_SOURCE_FILE_NAMES` build setting.
|
| sourceIdentifier: file:///Users/fabiani/Projects/Test/xcode/Test1/MyLibrary/Sources/MyLibrary/SwiftUIView.swift -> SwiftUIView.swift
| builtTargetDescriptions:
| static-MyLibrary1
